Bartalena, T., C. Leoni, and M. Pastore Trossello et al. 2010. “Hourglass Cystic Schwannoma of the Trochlear Nerve”. Acta Biomedica Atenei Parmensis 81 (2): 147-50. https://mattioli1885journals.com/index.php/actabiomedica/article/view/325.